Mail ordering has become a widely used way of buying goods. More and more companies offer virtual department stores, in which the customers can electronically put goods in a shopping cart that later will be transferred by the respective company into a dispatch order so that in a warehouse a shipment set comprising one or more items that have been ordered (and sometimes additional items such as samples, vouchers, invoices, etc.) can be assembled based on the respective dispatch order.
While assembling a shipment set in a warehouse of a specialized distributor is nowadays often done more or less fully automated, packaging the items to be shipped is still a challenge, in particular when a shipment set comprises several items of different sizes and in different quantity. Often, the items to be packaged are provided automatically to a person packaging the items manually. Depending on the size and number of the items, the person selects a suitable box size. Generally, the box is a cardboard box that upon packaging is assembled from a corresponding cardboard blank.
As used herein the term “blank” refers to a piece of cardboard having numerous rectangular panels delimited from each other via longitudinal and transverse crease lines and (optionally) incisions, facilitating the folding of a packaging from the blank.
As used herein the term “packaging” refers to all types of packaging means foldable from cardboard such as in particular boxes with or without lids, lids for boxes, inlays for boxes to hold individual items such as glasses and bottles etc.
As used herein, the term “panel” refers to substantially rectangular areas either of a stack of fanfold cardboard or of the blank. The panels of the blank form in the folded state the sides of a packaging such as the bottom, the top and the lateral sides of a box.
While it is obvious that for a person viewing a closed box the terms “length”, “width” and “height” depend on the respective perspective, from which the box is viewed, for sake of clarity and simplicity these terms as used herein relate to dimensions in specific directions. According to at least one aspect of the invention, the cardboard blanks are made from cardboard cut to length from a long web of so called double-faced corrugated cardboard, i.e. cardboard, in which a corrugated layer is sandwiched between two flat layers. As used herein, the length of the blank is the dimension of the blank in the direction of the length of the web from which it is cut, and the width of the blank is the dimension in the direction of the width of said web. Longitudinal crease lines run in the length direction, transverse crease lines in the width direction. Each panel of the blank has accordingly a length being the dimension of the panel in said length direction and a width being the dimension of the panel in said width direction. The dimensions of the panels determine the dimensions of the packaging folded therefrom, and as used herein the length of a packaging such as a box is the dimension of the box seen in the length direction of the blank, from which it is folded, the width of the box is the dimension of the box seen in said width direction of said blank, and the height of the box is the dimension of the box in a direction perpendicular to both, length and width direction.
US 2008 0020916 A1 discloses a box-making machine, which executes creasing and cutting acts to obtain a cardboard blank, which is then folded to obtain a packaging box from the blank. One or more embodiments of invention may be advantageously used in this type and similar types of machines and systems like for example the one disclosed in WO 2014 117817 A1.
To further automate the packaging process even in cases where the items vary in size and number, WO 2014 117817 A1 discloses a system that allows—within the boundaries imposed by the material used—creating a fully custom-sized box, i.e. a box, of which width, length and height are adapted to the respective content of the box. The box is created from cardboard continuously fed to the system by cutting out and creasing a custom-sized blank from which the box including panels to form a lid is folded automatically around one or more items to be packaged.
Double-faced corrugated cardboard has a rather high stiffness, which is advantageous for making packagings, but which prevents to wind a long (for example 1000 m long and about 0.8 m wide) cardboard web up for storing it in form of a roll. Hence, the web is fanfold into a stack of panels. However, fanfolding the cardboard has the disadvantage that there are transversal fold lines (hereinafter simply called “folds”) present in the source material at the positions where the panels are connected. As these folds are usually not at positions where crease lines are needed in a blank that is to be cut from the source material, they are typically called “unwanted folds” or “false folds”. This is especially the case, when the sizes of the blanks to be cut vary while the panels in a stack of cardboard have a fixed size.
When such false folds are present in a blank close to wanted crease lines, there is a high risk that the blank will not be folded at the intended crease lines, but at the false folds. Likewise, if a false fold is present close to the so-called leading edge of a blank, the first panels in the transport direction of the blank may be not be gripped properly or, if these first panels are panels used for closing the packaging, may be difficult to attach for example by hot melt glue to a respective other panel. Thus, false folds may cause undesired effects during or after the folding process, may jam in the machine, may cause stops of the complete packaging system and may result in an undesired appearance and insufficient stability of the packaging. Note that the terms “leading” and “ending” edge originate from the transport direction, in which cardboard fanfold cardboard is fed. The leading edge of the blank is the ledge that formed—prior to cutting-off a piece of cardboard for creating the blank—the leading edge of the web. Once cut-off, the opposite edge of the cardboard piece cut-off forms the end of the blank and is therefore called the “ending edge”
In order to solve the problem of false folds, an apparatus and a method have been suggested in WO 2014 188010 A2 that allow rigidifying cardboard having at least one transversal fold and thus obtaining packaging material with increased stiffness from a stack of fanfold cardboard by applying creasing means to form for example line-shaped indentations on at least one side of said cardboard, wherein at least some of said indentations intersect the unwanted transversal folds, which increases the stability of the cardboard at the respective area. However, additional crease lines may—depending on the specific blank layout—also lead to an undesired appearance and only work well if there is a certain minimum distance between an unwanted fold with intersecting stabilizing indentations and a wanted crease line parallel to the unwanted fold.
While the apparatus and method disclosed in WO 2014 188010 A2 work perfectly well in many cases, just forming indentions that intersect false folds may not in all cases lead to sufficient stiffness, in particular when rather thin material is used and/or the formed packagings are rather big and/or items to be packaged are rather heavy.
Different other approaches to handle the problems associated with unwanted folds present in fanfold cardboard are disclosed in US 2018 0201465 A1. If it is determined that an unwanted fold would be present within a certain distance to a wanted crease line, depending on the position of the unwanted fold either a piece of cardboard containing the unwanted fold is completely cut away or the leading edge of the cardboard presently processed is cut off to a certain amount in order to ensure that the unwanted fold, although still present in the cardboard, would be at a certain minimum distance to the wanted crease lines. However, these approaches are necessarily associated with the production of waste material. If a packaging system using custom-sized boxes allows to forecast at least two consecutive shipment sets needing differently sized boxes, US 2018 0201465 A1 proposes to check, if one of the boxes would need a blank, in which the unwanted fold would be at a position not interfering with the wanted crease lines and, if so, to shift the order of packaging the shipment sets accordingly. However, in high speed automated packaging systems this would require additional handling and “parking” areas, in which a shipment set that is currently in front of another set but for which a box is required, whose blank would have an unwanted fold close to a wanted crease line, could be “parked” in order to let another shipment set be processed first, if this shipment set requires a card board blank, in which the unwanted fold has the certain minimum distance to a wanted crease line. In particular if the shipment sets contain numerous items varying in size that are manually arranged for being automatically packaged, it is difficult to predict well in advance, what actual dimensions a box for this specific shipment set would need to have. Accordingly, just one parking area may not be sufficient in order to avoid that always blanks can be produced, in which the unwanted folds have sufficient distance to wanted crease lines.